Contact structure for electrical circuit controllers



June 8, 1937. J. F. EBERT Er Al.`

CONTACT STRUCTURE FOR ELECTRICAL CIRCUIT CONTROLLERS Filed May 24, 1954 naarzfr 1% F Eber-Z" ZHWMECZJYQMP@ Patented June 8,

orFIcE I CONTACT STRUCTURE FOR ELECTRICAL CONTROLLERS Joseph F. Ebert, Hollis, and Edmund M Squire Brooklyn, N. Y., assignors to Signal Engineer- I ing & Manufacturing Company, New York,

N. Y., a corporation of Massachusetts Application May 24, 1934, Serial No. 727,312

4 Claims. (Cl. 20D-166) 'Ihe present invention relates to electrical circuit controllers, and has for its object to provide an improved contact structure for devices of this character that is adapted to handle the flow of electrical currents with uniform contact pressure and without destructive arcing.

The present invention relates particularly to a circuit controller of the type employing a pivoted member adapted by its movement to carry w contacts into and out of operative relation with cooperating stationary contacts. 'I'he improved contact structure of the invention is incorporated in the movable member so as to always engage the stationary contacts with an even pressure, and in- 15 operation, isy characterized by the substantial elimination of arcing, high current carrying capacity, as well as the absence of any iiexible leads for conducting current to the movable contacts.

The above and other advantageous features of the invention will hereinafter more fully appear from the following description with reference to the accompanying drawing, in which:-

Fig. 1 is a` view in side elevation of a circuit controller embodying the invention. with the contacts in non-current carrying position.

Fig. 2 is a view similar to Fig. l, showing the contacts in current carrying position.

Fig. 3 is a view in front elevation, on an enlarged scale, of the contact structure remove from the circuit controller.

Fig. 4 is a rear elevation of Fig. 3.

Fig. 5 is a vertical sectional view-along the line 5-5 of Fig. 3. 35 Fig. 6 is a sectional view similar to Fig. 5,

showing the contacts of the controller in engagement.

Fig. 7 is a view similar to Fig. 3. showing a modification of the invention.

FlFig. 81s a sectional view along the line 8-8 of Fig. 9 is a view in side elevation of a circuit controller embodying the modied contact construction of Fig. 7.

Like reference characters referto like parts in the diilerent figures. I

Referring first to Figs. 1 and 2, the invention is shown, for purposes of illustration, as being embodied in a circuit controller of the Arelay type, 50 the essential elements of which comprise an insulating base I carrying a magnetic core 2, one leg of which is surrounded by an' energizing winding l. A magnetic armature I pivotally supported onl the lower end of the other core leg isadapted to 55 be raised upon energization of the winding 3 the parts shown in and held in the' position of Fig. 2, deenergization of the winding 3 permitting the amature 4 to fall back into the position of Fig. 1 under the influenceof gravity. The armature I carries one or .more upwardly extending arms 5, and each arm 5 is provided at its free end with a contact structure 6 embodying the present invention and adapted to cooperate with spaced stationary contacts l and 8 mounted on the base i, in a manner which will next be described.

As best shown in Figs. 3, 4 and 5, the contact structure E consists o! a. plate 9 carrying a pair of contacts i having substantially the same spacing as the stationary contacts 'i and 8.v The contacts i0 extend through-openings Il provided in the upper end of the arm 5, which openings ii are oi' appreciably larger diameter than the contacts i0. 'I'he plate 9 also provides a central opening i2 which freely receives a pin i 3 mounted on the armfi between the openings I i. The oppo site end oi the pin i3 provides a head I4 and a spring i5, surrounding the pin i3 between the head Il and the plate 9, exerts a pressure tending to hold the plate 9 in contact with the arm 5.

With the winding I deenergized and the armature 4 occupying the position of Fig. 1, the -plate 9 carrying the contacts I0 is held in engagement with the arm by the pressure of the spring i5.

Upon energization of the winding 3, the armature 4 is drawn upwardly to the position of Fig.

2, thereby carrying the contacts I0 on the arm 5 into engagement with the stationary contacts 'I and 8. Owing to the fact that the arm 5 is still inclined somewhat from the vertical, as the contacts i0 engage the stationary contacts 1 and 8, it follows that the lower contact l0 will engage the contact 8 somewhat in advance of engagement of the contact 'I by the upper contact I0. When this occurs, the plate 9 yields against the pressure of the spring il, and separates from the arm 5 as the contacts come into complete ensagement. The yielding of the plate 9 is shown on a somewhat exaggerated scale in Fig. 6, from which .iti is apparent that there results a very even engagement between the laces of the` contacts 1, 8 and I0. Since the plate 9 is, in eiIect,

.floating atthe end of the movable arm 5, the

contacts I0 are adapted to adjust themselves to the stationary contacts 'i and 8, with their engaging faces always in parallel relation and with a substantial elimination of arcingl due to uneven wear of the contact surfaces. Upon deenergizationoi the winding 3 and dropping of the armature 4, the contacts I0 disengage the contacts 1 and 8 in the reverse order of their engagement,

`with the contact faces remaining substantially parallel until the final separation.

. Referring now to Figs. 7 and 8, there is shown a modification of theinvention in which spaced arms Is carried by the armature d are adapted to carry between them a contact member Il adapted to cooperate with stationary contacts on opposite sides thereof, as indicated in Fig. 9. The

upper ends of the arms IB provide alined open- 10 ings I8 and pairs of contacts I9 and 20 carried by the member I1 project through these openings I8. Normally, the contact member I1 -is yieldingly clamped between the arms Il by the in engagement with the stationary contacts 22 and 24 by the weight of the amature 4, which 25 may be augmented by the provision of an extra weight 4a. With the contacts 20 engaging stationary contacts 23 and 24 as indicated in dotted lines in Fig. 8, it is obvious that the contact member Il, floating between the upper ends oi the arms I6, is adapted to adjust itself to insure proper engagement between the contact surfaces. 'Upon liftingo'f the amature 4 due to energization of the winding 3, separation of the contacts 2l from the stationary contacts permits the contact member I1 to resume its oating position between the arms I8. Therefore, engagement of the left hand contacts i8 with stationary contacts 'i' and 8' is also accompanied by self-ad- Justment of the member I1 to insure uniform 40 pressure between the engaged contact surfaces. From the foregoing, it is apparent that by the present invention there is provided an improved contact structure for circuit controllers characterizedy by its ability to maintain even contact pressure at all times with a substantial elimination of arcing and increased current carrying capacity. Furthermore, since the floating contact members 6 and Il are adapted to bridge both sides of a circuit, including the spaced stationary 5o contacts, the need for flexible leads for conducting current to the movable contact members'is entirely eliminated, nor is there any necessity for making the movable arms d and i@ of conducting material.

We claim:

1. In a device of the class described, the combination with spaced stationary contacts and a 5 pivotaliy mounted arm providing openings near' its free endend movable toward or away from' said stationary contacts, of a plate freely supported on said arm, a spring normally maintaining said plate in engagement with saidi arm and i0 contacts carried by said plate and extending through said arm openings for engagement with said stationary contacts, said plate by its free and yieldable vmounting on said arm permitting self- `adjustment of the engaged contacts independl5 ently of said arm. l

2. In a device of the class described, the coml bination with opposed pairs of stationary contacts and a pivotally mounted member providing openings near its free end and movable toward 20 or away from either pair of said stationary contacts, cf a plate yieldingly supported on said pivoted member and providing oppositely extending spaced contacts movable freely in said openings for cooperation with said xed contacts. 25

3. In a device of the class described, the combination withoppositely disposed pairsV of spaced stationary contacts and a pivotally mounted member carrying spaced arms providing allned openings near their free ends, of a contactstruc- 30 ture mounted between said arms at their free ends and carrying oppositely extending contacts movable freely through said arm openings for` cooperation with either pair of said stationary contacts, and means for pressing said arms to- 35 gether for maintaining said contact structure in position.

4. In a device of the class described, the combination with spaced stationary contacts and a pivotally mounted arm of relatively stiff mate- 40 rial providing openings near its free end and movable toward or away from said stationary contacts, of a pin projecting from said ann between said openings, a plate loosely mounted on said pin and yieldingly maintained in engage- 46 ment with said arm, and contacts carried by said I plate extending freely through the openings of said arm for self-alining engagement with said stationary contacts.

-JOSEPH F. .EBERT 50 ED M. SQUIRE 

